Titanium nitride coated bit.
This is a fairly common type of milling bit, a double-sided square end mill. It is intended for use in a vertical milling machine to cut steel, aluminum, brass, or other such metals. The base material is high-speed steel, a tough, hard alloy that by itself is good enough to cut a wide range of materials. The gold color comes from a titanium nitride surface coating, which is even harder, and allows the bit to cut abrasive metals for longer before becoming dull. TiN coated bits are not as good as tungsten carbide bits, but they are a whole lot cheaper.Source: ENCOContributor:Theodore GrayAcquired:2 December, 2007Text Updated:2 December, 2007Price: $10Size: 3"Purity: <1%